In this report, the authors create a framework that can be used to rigorously consider the trade-offs involved in U.S. military intervention decisions following the outbreak of a war or crisis. This framework can provide a better understanding of the relationships between intervention timing, intervention size, and intervention outcomes to inform future debates about whether, when, and with what size force to undertake a military intervention.

This report evaluates the potential for further escalation in the conflict in Ukraine, including the prospects for escalation to Russian nuclear use. The report is intended to inform U.S. and NATO policymakers as they consider how to avoid further escalation of the conflict while assisting Ukraine in its efforts to defeat the Russian invasion and to better inform the public debate around these issues.

As the U.S. National Defense Strategy recognizes, the United States is currently locked in a great-power competition with Russia. This report seeks to define areas where the United States can compete to its own advantage. It examines Russian vulnerabilities and anxieties; analyzes potential policy options to exploit them; and assesses the associated benefits, costs, and risks, as well as the likelihood of successful implementation.

Despite Russia’s relatively small global economic footprint, it has engaged in more interventions than any other U.S. competitor since the end of the Cold War. In this report, the authors assess when, where, and why Russia conducts military interventions by analyzing the 25 interventions that Russia has undertaken since 1991, including detailed case studies of the 2008 Russia-Georgia War and Moscow’s involvement in the ongoing Syrian civil war.

The Maidan Revolution in Ukraine created an opportunity for change and reforms in a system that had resisted them for 25 years. This report examines Ukraine’s security sector—assessing what different institutions need to do and where gaps exist—and offers recommendations for the reform of Ukraine’s security and defense institutions that meet Ukraine’s security needs and align with Euro-Atlantic standards and approaches.

Aid flowing into Syria is intended to determine the outcome of the conflict between rebel factions and Damascus. Instead, it could perpetuate the civil war and ignite larger regional hostilities that could reshape the political geography of the Middle East. This report examines the main factors likely to contribute to or impede the spread of violence from civil war and insurgency in Syria, and then examines how they apply to neighboring states.

The challenge of deterring territorial aggression is taking on renewed importance, yet discussion of it has lagged in U.S. military and strategy circles. The authors aim to provide a fresh look, with two primary purposes: to review established concepts about deterrence, and to provide a framework for evaluating the strength of deterrent relationships. They focus on a specific type of deterrence: extended deterrence of interstate aggression.